①Coma. Response to the entire environment disappears.

② Various reflections disappear. The pupils have no light reflex and are dilated.

③ Spontaneous breathing disappears. This includes still not breathing spontaneously after stopping artificial respiration for 3 minutes.

④ If not maintained artificially, blood pressure will drop sharply.

⑤ Even if stimulation is given, the EEG will show a straight line. The above situations should exclude patients with hypothermia (less than 23°C) and drug abusers.

Repeat the above test 24 hours later, the result remains unchanged